If log y = tan–1 X, show that : (1+x2)y2+(2x–1) y1=0.

Note: y2 represents second order derivative i.e. and y1 = dy/dx


Given,


log y = tan–1 X


y = ……equation 1


to prove : (1+x2)y2+(2x–1)y1=0


We notice a second order derivative in the expression to be proved so first take the step to find the second order derivative.


Let’s find


As


So, lets first find dy/dx



Using chain rule, we will differentiate the above expression


Let t = tan–1 x => []


And y = et



…….equation 2


Again differentiating with respect to x applying product rule:



Using chain rule we will differentiate the above expression-



[using & ]




Using equation 2 :



(1+x2)y2+(2x–1)y1=0 ……proved


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